Stores: the Installed tab draws what its count counts

The tab's count came from the installs on disk and its grid from the
library filtered by id, so two installs could read Installed (2) over an
empty grid. Both now come from installedCards: each install joined to its
library item by store id, or by title when the ids differ, else a card
made from the sidecar's own title and art.

docs/progress-log.md

@@ -144,6 +144,9 @@ without it and Setup says "Stores engine not built").
   (`token`, `__token__`, `f_token`, `hdnts`, access/refresh/id tokens, `code=`) and Authorization /
   Cookie headers are blanked outside URLs too. `StoreLogTest` covers a GOG secure link and an Epic
   Akamai URL. The engine's own logcat lines (tag `EpicNative` etc.) are written on the native side.
+- **Installed tab empty under "Installed (2)" (device):** the count came from the installs on disk,
+  the grid from the library filtered by id. Both now come from `installedCards`: each install joined
+  to its library item by id (or title), else a card from the sidecar's title and art.
 - **GOG rows (device, DOOM + DOOM II):** bytes read "0 B" instead of blank; GOG and Amazon report
   their size on disk from the manifest; their Install stage counts its finishing steps (record and
   launcher, art, Steam) instead of sitting empty - GOG writes files in place while downloading, so